Violet vat dyestuff and process of making same.



- UNITED STATES OPATENT Q'QQFFIQE.

ARMIN GROB, OF BASICL, SWI'IZERLAND, ASSIGNOR TO THE FIRM OF BASLE CHEMICAL \VO RKS OF BASEL, SWITZERLAND.

Specification 01" Letters Patent.

Patented Nov. 2 1908.

Application filed June 23, 1908. Serial No. 439,865.

agent, as for instance sodium carbonate,

piperid in otcuto the said hot solution or suspension.

The nmnutaeturc of the new dyestutf is explained by the. following oxan'iplc:

Example: 18.2 parts of aceuaphthenw quinone and 13.3 parts of indoxyl are suspended in 1000 parts of alcoholot' 90 per 0on1. and thonnxtnrc is hcatcd. By addlng an aqueous solution of parts of calcinatcd soda or a trace of piperidin to the hot nixture the dycstutl scpara tes at once in vio-' let scales which arc isolated by filtration.

The dycstutf dissolves in concentrated sulfuric acid to a green solution and on addition of water it is precipitated therefrom as violet flakes. It is diflicultly soluble in hot alcohol with a blue-violet coloration, but more easily in hot benzene with a red-violet coloration. From its solution in benzene the dyestutf can be rccrystallizccl and thus be separated from a small quantity of indigo,

which is formed simultaneously.

\Vith an alkaline solution sodium hydrosulfilo, the dycstufl' iel(ls a, reddish, graywiolet rat from which unmordanted cotton clycd violet shados.

\Vhat i claim is:

1. The described process for the manufacture of a \iolot dyestu tf consisting in heating acenaphthcnoquinone with indoxyl in aqueous alcohol and in adding a small quantity of a condensing agent to the hot mass thus obtained.

2. The described process for the manufacturc of a violctdycstuff consisting in heating acena1 hthcnc-quinono with indoxyl in'aqueous alcohol and in adding'a small quantity of soda to the hot mass thus obtained.

3. As a new article of manufacture.the heroin-described violet; vat-dyestufl'. derived from :u-vcnapht hono qninonc' and indoxyl, soluble in concentrated sulfuric acid with a green coloration diflicultly soluble in hot alcohol with a blue-violet coloration, more easily soluble in hot benzene with a IGd-ViO: let coloration and dyeing uumordanted cot ton froma rodlmed alkalino'vat in violet shades.

In Witness whereotl havehercunto signed my name this 12th day of June 1908, the presence of two subscribing witnesses.

ARMIN GROB.

Witnesses AMAND BITTER, ERNST Manna. 

